SIMULTANEOUS BINDING OF BORON AND AMMONIUM CATION BY A PSEUDOCRYPTAND - SYNTHESIS, X-RAY-ANALYSIS AND SOLUTION STUDIES BY NMR-SPECTROSCOPY

Treatment of the macrocyclic compound 1 bearing two catecholate moieties with equimolar amounts of B(OH)(3) and aqueous NH3 in a H2O-EtOH mixture gave exclusively the ammonium inclusion complex 2 which was then studied both in solution and in the solid state; the selectivity sequence NH4+ > Na+ > Cs+ in CD3OD solution was obtained and the ammonium ion complex 2 was found to be more stable than the ([222], NH4+) complex by at least 3 orders of magnitude.